title: Solitary vortices supported by localized parametric gain.
abstract: We demonstrate the existence and stability of bright vortex solitons sustained by a ring-shaped parametric gain, for both focusing and defocusing Kerr nonlinearities in lossy optical media. With the defocusing nonlinearity, the vortices are stable at all values of the detuning parameter, while under the focusing nonlinearity their stability region is limited to some positive values of the detuning. Unstable vortices in the focusing medium transform into stable rotating azimuthons.
authors.affiliation: State Key Laboratory of Advanced Optical Communication Systems and Networks, Physics Department, Shanghai Jiao Tong University, Shanghai 200240, China.
authors.forename: Changming
authors.initials: C
authors.lastname: Huang
authors.forename: Fangwei
authors.initials: F
authors.lastname: Ye
authors.forename: Boris A
authors.initials: BA
authors.lastname: Malomed
authors.forename: Yaroslav V
authors.initials: YV
authors.lastname: Kartashov
authors.forename: Xianfeng
authors.initials: X
authors.lastname: Chen